H110 BTC Pro issue

[Manlost111]

Hi Guys,
Needed a bit of help. I have been mining with Asrock H110 BTC Pro for last week with 9 GPUs.
Since yesterday, My mobo has stop detecting 4 GPUs and only showing 5 GPUs.
I first thought it could be a riser issue, I have tried to switch riser but it didn't work.
I have noticed that when I put the riser in the black coloured PCI-e slot, it works but when I swap the same GPU to the white slot it stops working.
The motherboard has CPU,Mobo, 2xmolex and 1 sata power plug which I have put them correctly.
I can't figure it out why it is detecting?
I have check simplemining, hiveOS and windows but not working.
Any help will be appreciated.

[MfMax]

Try to put gpus in order.

Black slots first.

Here is scheme.

White slots  are gpu 6,9,10,11,12,7,8

Black slots are gpu 1,0,2,3,4,5

So you should leave 3 white slots empty ,on the right side from long black slot, 10,11,12.

Thats if you have  9 gpus.

[chem96]

motherboard Bios --> disable onboard audio and onboard video.
help sometimes...